Mathematical physics

Higher algebra has become important throughout mathematics physics and mathematical physics and this conference will bring together leading experts in higher algebra and its mathematical physics applications. In physics the term algebra is used quite broadly any time you can take two operators or fields multiply them and write the answer in some standard form a physicist will be happy to call this an algebra. Higher algebra is characterized by the appearance of a hierarchy of multilinear operations (e.g. A_infty and L_infty algebras). These structures can be higher categorical in nature (e.g. derived categories cosmology theories) and can involve mixtures of operations and co-operations (Hopf algebras Frobenius algebras etc.). Some of these notions are purely algebraic (e.g. algebra objects in a category) while others are quite geometric (e.g. shifted symplectic structures). An early manifestation of higher algebra in high-energy physics was supersymmetry. Supersymmetry makes quantum field theory richer and thus more complicated but at the same time many aspects become more tractable and many problems become exactly solvable. Since then higher algebra has made numerous appearances in mathematical physics both high- and low-energy. A tell-tale sign of the occurrence of higher structures is when classification results involve cohomology. Group cohomology appeared in the classification of condensed matter systems by the results of Wen and collaborators. Altland and Zirnbauer s "ten-fold way" was explained by Kitaev using K-theory. And Kitaev's 16 types of vortex-fermion statistics were classified by spin modular categories. All these results were recently enhanced by the work of Freed and Hopkins based on cobordism theory. In high energy physics cohomology appears most visibly in the form of "anomalies". The Chern--Simons anomaly comes from the fourth cohomology class of a compact Lie group and the 5-brane anomaly is related to a certain cohomology class of the Spin group. The classification of conformal field theories involves the computation of all algebras objects in certain monoidal categories which is a type of non-abelian cohomology. Yet another important role for higher algebra in mathematical physics has been in the famous Langlands duality. Langlands duality began in number theory and then became geometry. It turned into physics when Kapustin and Witten realized geometric Langlands as an electromagnetic duality in cN=4 super Yang--Mills theory. Derived algebra higher categories shifted symplectic geometry cohomology and supersymmetry all appear in Langlands duality. The conference speakers and participants drawn from both sides of the Atlantic and connected by live video streams will explore these myriad aspects of higher algebra in mathematical physics.

The Kitaev quantum double models are a family of topologically ordered spin models originally proposed to exploit the novel condensed matter phenomenology of topological phases for fault-tolerant quantum computation. Their physics is inherited from topological quantum field theories, while their underlying mathematical structure is based on a class of Hopf algebras. This structure is also seen across diverse fields of physics, and so allows connections to be made between the Kitaev models and topics as varied as quantum gauge theory and modified strong complementarity. This workshop will explore this shared mathematical structure and in so doing develop the connections between the fields of mathematical physics, quantum gravity, quantum information, condensed matter and quantum foundations.

In the past five years their have a been number of significant advances in the mathematics of QFT on manifolds with boundary.  The work of Cattaneo, Mnev, and Reshitihkin--beyond setting rigorous foundations--has led to many computable and salient examples.  Similarly, the work of Costello (specifically projects joint with Gwilliam and Si Li) provides a framework (and deformation/obstruction) for the observable theory of such theories with boundary/defects. There are related mathematical advances: constructible factorization algebras and higher category theory as pioneered by Lurie and the collaboration of Ayala, Francis, and Tanaka. The goal of the workshop is to bring together the leading experts in this multi-faceted subject.The structure of the workshop will be such as to maximize the exchange of knowledge and collaboration. More specifically, the morning sessions will consist of several lecture series, while the afternoons will be reserved for research working groups. The mornings will communicate the essential ideas and techniques surrounding bulk-boundary correspondences and perturbative AKSZ theories on manifolds with boundary/corners. The afternoons will be research driven and focus on specific problems within the following realms: the interaction of renormalization with cutting/pasting, aspects of the AdS/CFT correspondence, cohomological approaches to gravity, and the observable/defect theory of AKSZ type theories.